1. Field of the Invention
The present invention relates to an optical module.
2. Description of the Related Art
An optical module used in an optical communication device generally includes an optical fiber, a lens and a light-receiving element. In the optical module, the optical fiber causes an optical signal input from the outside of the optical module to exit to the lens, and the lens focuses the optical signal on a light reception surface of the light-receiving element. Then, the light-receiving element converts the received optical signal to an electric signal.
However, there may be a problem of light return in which a part of the optical signal exiting from the optical fiber via the lens to the light-receiving element is reflected on the light reception surface of the light-receiving element, and the reflected light returns to the optical fiber. In this case, as a result, noise is generated in the electric signal of the optical communication device.
As the technology for suppressing the noise due to the reflection of the optical signal on the light reception surface of the light-receiving element as described above, there is known a technology of disposing the light-receiving element to deviate from the center of the optical axis of the lens (see US Patent Application Publication No. US2009/0263082), or a technology of disposing the light-receiving element so as to incline the normal direction on the light reception surface of the light-receiving element with respect to the optical axis of the lens (see US Patent Application Publication No. US2010/0148041).